org.janusgraph.diskstorage.keycolumnvalue.cache

Class ExpirationKCVSCache

java.lang.Object

org.janusgraph.diskstorage.keycolumnvalue.KCVSProxy

org.janusgraph.diskstorage.keycolumnvalue.cache.KCVSCache

org.janusgraph.diskstorage.keycolumnvalue.cache.ExpirationKCVSCache

All Implemented Interfaces:

KeyColumnValueStore

public class ExpirationKCVSCache
extends KCVSCache

Author:

Matthias Broecheler (me@matthiasb.com)

Field Summary

Fields inherited from class org.janusgraph.diskstorage.keycolumnvalue.cache.KCVSCache

NO_DELETIONS

Fields inherited from class org.janusgraph.diskstorage.keycolumnvalue.KCVSProxy

store

Fields inherited from interface org.janusgraph.diskstorage.keycolumnvalue.KeyColumnValueStore

NO_ADDITIONS

Constructor Summary

Constructors

Constructor and Description
ExpirationKCVSCache(KeyColumnValueStore store, String metricsName, long cacheTimeMS, long invalidationGracePeriodMS, long maximumByteSize)

Method Summary

Modifier and Type	Method and Description
void	clearCache()
void	close() Closes this store
void	forceClearExpiredCache()
Map<SliceQuery,Map<StaticBuffer,EntryList>>	getMultiSlices(MultiKeysQueryGroups<StaticBuffer,SliceQuery> multiKeysQueryGroups, StoreTransaction txh) Retrieves the list of entries (i.e.
EntryList	getSlice(KeySliceQuery query, StoreTransaction txh) Retrieves the list of entries (i.e.
Map<StaticBuffer,EntryList>	getSlice(List<StaticBuffer> keys, SliceQuery query, StoreTransaction txh) Retrieves the list of entries (i.e.
void	invalidate(StaticBuffer key, List<CachableStaticBuffer> entries)

Methods inherited from class org.janusgraph.diskstorage.keycolumnvalue.cache.KCVSCache

getMultiSlicesNoCache, getSliceNoCache, getSliceNoCache, hasValidateKeysOnly, incActionBy, mutate, mutateEntries, unwrapTx

Methods inherited from class org.janusgraph.diskstorage.keycolumnvalue.KCVSProxy

acquireLock, getKeys, getKeys, getKeys, getName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExpirationKCVSCache

public ExpirationKCVSCache(KeyColumnValueStore store,
                           String metricsName,
                           long cacheTimeMS,
                           long invalidationGracePeriodMS,
                           long maximumByteSize)

Method Detail

getSlice

public EntryList getSlice(KeySliceQuery query,
                          StoreTransaction txh)
                   throws BackendException

Description copied from interface: KeyColumnValueStore

Retrieves the list of entries (i.e. column-value pairs) for a specified query.

Specified by:

getSlice in interface KeyColumnValueStore

Overrides:

getSlice in class KCVSProxy

Parameters:

query - Query to get results for

txh - Transaction

Returns:

List of entries up to a maximum of "limit" entries

Throws:

BackendException - when columnEnd < columnStart

See Also:

KeySliceQuery

getSlice

public Map<StaticBuffer,EntryList> getSlice(List<StaticBuffer> keys,
                                            SliceQuery query,
                                            StoreTransaction txh)
                                     throws BackendException

Description copied from interface: KeyColumnValueStore

Retrieves the list of entries (i.e. column-value pairs) as specified by the given SliceQuery for all of the given keys together.

Specified by:

getSlice in interface KeyColumnValueStore

Overrides:

getSlice in class KCVSProxy

Parameters:

keys - List of keys

query - Slicequery specifying matching entries

txh - Transaction

Returns:

The result of the query for each of the given keys as a map from the key to the list of result entries.

Throws:

BackendException

getMultiSlices

public Map<SliceQuery,Map<StaticBuffer,EntryList>> getMultiSlices(MultiKeysQueryGroups<StaticBuffer,SliceQuery> multiKeysQueryGroups,
                                                                  StoreTransaction txh)
                                                           throws BackendException

Description copied from interface: KeyColumnValueStore

Retrieves the list of entries (i.e. column-value pairs) for each provided SliceQuery for all respective given keys together.
The default implementation of this method is not optimized and instead uses blocking calls for each separate SliceQuery via KeyColumnValueStore.getSlice(List, SliceQuery, StoreTransaction).
It is highly advisable to overwrite this implementation and use optimized implementation which requests all Slice queries in parallel by using asynchronous slice queries evaluation / grouped slice queries evaluation / parallel slice queries evaluation using a thread pool or any other optimized queries evaluation which can retrieve results for all requested queries (SliceQuery) in the shortest time possible.
Backend implementations which are not using blocking IO calls to the underlying storage backend (i.e. `in-memory` storage implementation) don't need to overwrite or optimized this method because both parallelized implementation and a sequential implementation will be performed the same for such storage implementations.

Specified by:

getMultiSlices in interface KeyColumnValueStore

Overrides:

getMultiSlices in class KCVSProxy

Parameters:

multiKeysQueryGroups - List of Tuples where key is a List of SliceQuery queries which has to be performed and a value is a list of keys for which all the queries have to be performed.

txh - Transaction

Returns:

The result of the query for each of the given SliceQuery and each of the given key. EntryList result should be provided for each of the StaticBuffer of each of the SliceQuery.

Throws:

BackendException

clearCache

public void clearCache()

Specified by:

clearCache in class KCVSCache

invalidate

public void invalidate(StaticBuffer key,
                       List<CachableStaticBuffer> entries)

Specified by:

invalidate in class KCVSCache

forceClearExpiredCache

public void forceClearExpiredCache()

Specified by:

forceClearExpiredCache in class KCVSCache

close

public void close()
           throws BackendException

Description copied from interface: KeyColumnValueStore

Closes this store

Specified by:

close in interface KeyColumnValueStore

Overrides:

close in class KCVSProxy

Throws:

BackendException